__calc__
__calc__
Traceback (most recent call last):
  File "/home/vvs/Programming/dimcalc/dimcalc.py", line 134, in on_add_dim_button_clicked
    Dim(dim_value, up_tolerance, un_tolerance))
  File "/home/vvs/Programming/dimcalc/dimension.py", line 196, in add_dim
    self.__calc__()
  File "/home/vvs/Programming/dimcalc/dimension.py", line 291, in __calc__
    r = eval(f)
  File "<string>", line 1
     +Dim(,0,0)
          ^
 SyntaxError: invalid syntax
